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We report a series of lipidated α-AApeptides that mimic the structure and function of natural antimicrobial lipopeptides. Several short lipidated α-AApeptides show broad-spectrum activity against a range of clinically related Gram-positive and Gram-negative bacteria as well as fungus. Their antimicrobial activity and selectivity are comparable or even superior to the clinical candidate pexiganan as well as previously reported linear α-AApeptides. The further development of lipidated α-AApeptides will lead to a new class of antibiotics to combat drug resistance.

To improve the reliability and optimize the maintenance strategy of a large‐scale wind farm, a health condition assessment method of wind turbine generator system (WTGS) based on multiple turbines cooperation is presented in this paper. First, a health condition assessment framework is established by analyzing the existing monitoring characteristics of SCADA system. Second, to quantify the health condition of a WTGS, the concept of synthetic degradation factor is introduced and calculated using variable weight of assessment indices. Third, in order to acquire the health level of a WTGS effectively, based on the idea of multiple turbines cooperation, the health condition assessment model is proposed by utilizing the moving average method and quantile algorithm. Finally, by using SCADA monitoring data of a wind farm with 33 × 1.5 MW WTGSs including temperature, pressure, vibration, and so on; the processes of condition assessment are performed, and the effectiveness is also compared to a traditional assessment method with the fixed threshold. The results show that the condition assessment that utilizes the proposed method can acquire the change of health conditions and has a better coherence with real health conditions. [ABSTRACT FROM AUTHOR]

Foldamers offer an attractive opportunity for the design of novel molecules that mimic the structures and functions of proteins and enzymes including biocatalysis and biomolecular recognition. Herein we report a new class of nonnatural helical sulfono-γ-AApeptide foldamers of varying lengths. The crystal structure of the sulfono-γ-AApeptide monomer S6 illustrates the intrinsic folding propensity of sulfono-γ-AApeptides, which likely originates from the bulkiness of tertiary sulfonamide moiety. The two-dimensional solution NMR spectroscopy data for the longest sequence S1 demonstrates a 10/16 right-handed helical structure. Optical analysis using circular dichroism further supports well- defined helical conformation of sulfono-γ-AApeptides in solution containing as few as five building blocks. Future development of sulfono-γ-AApeptides may lead to new foldamers with discrete functions, enabling expanded application in chemical biology and biomedical sciences. [ABSTRACT FROM AUTHOR]

Foldamers offer an attractive opportunity for the design of novel molecules that mimic the structures and functions of proteins and enzymes including biocatalysis and biomolecular recognition. Herein we report a new class of nonnatural helical sulfono-γ-AApeptide foldamers of varying lengths. The crystal structure of the sulfono-γ-AApeptide monomer S6 illustrates the intrinsic folding propensity of sulfono-γ-AApeptides, which likely originates from the bulkiness of tertiary sulfonamide moiety. The two-dimensional solution NMR spectroscopy data for the longest sequence S1 demonstrates a 10/16 right-handed helical structure. Optical analysis using circular dichroism further supports well- defined helical conformation of sulfono-γ-AApeptides in solution containing as few as five building blocks. Future development of sulfono-γ-AApeptides may lead to new foldamers with discrete functions, enabling expanded application in chemical biology and biomedical sciences., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The creation and development of nonnatural peptidomimetics has become an area of increasing significance in bioorganic and chemical biology. A wide range of new peptide mimics with novel structures and functions are urgently needed to be explored in order to identify potential drug candidates and targeted probes, and to study protein functions. AApeptides are a new class of peptide mimics based on chiral PNA backbone. They are resistant to proteolytic degradation and have limitless potential for diversification. They have been found to have a wide variety of biological applications including cellular translocation, disruption of protein-protein interactions, formation of nanostructures, antimicrobial activity, etc. The synthesis of AApeptides is modular and straightforward. In this chapter, methods for the synthesis of AApeptides (including different subclasses) are described.

Besides the common issue of drug-resistance, the conventional approaches for cancer diagnostics and treatment are constantly challenged by poor selectivity and limited access to neoplastic cells, which not only lead to the dose-limiting effect on the tumor region, but also bring side-effects to healthy cells/tissues. In recent years, a novel strategy has arisen to target the vasculature of tumors for drug-delivery and molecular imaging, based on the success of anti-angiogenic therapy. In addition to being easily accessible, the endothelial cells of tumor vasculature are also genetically stable and thus do not develop drug-resistance, making them ideal targets for chemotherapeutics and biomedical imaging. Among various ligands identified so far, the Asn-Gly-Arg (NGR) tripeptide can specifically target the neovasculature via interaction with the aminopeptidase N (APN/CD13) receptor which is highly up-regulated in the membranes of endothelial tumor cells. NGR-directed drug delivery as well as molecular imaging have therefore been undergone development, and appear to be intriguing approaches in current cancer research. Herein we highlight some recent developments of the NGR peptide based cancer therapy including drug-delivery and imaging studies, with future perspectives. Some of these agents have been under clinical trials, indicating promising future for the NGR-based drugs.